To my knowledge unless very recently changed...Carilion Transportation is actually on 155.385 in Roanoke. I think the database has them listed as 156.240. 463.625 used to be a crosspatch with what I think was the Radford operations (Carilion runs as EMS in Radford). They may be on this still in Radford. 155.385 also is used for air operations (Lifeguard 10 & 11). I'm not sure of the other "stations" as they have agreements with many other jurisdictions to answer EMS calls, for example Franklin Co. and Bedford Co. They use the local EMS frequencies in these areas.
Hope this helps,
Kenny